Research On The Pretreatment Of Dioscorea Zingiberensis C.H.Wright Diosgenin Wastewater

Dioscorea Zingiberensis C.H.Wright diosgenin wastewater is a high concentration of hard-degradable industrial wastewater,which contains high concentration of sugar,high concentration of organic matter,high Ammonia nitrogen content,a lot of hard-degradable surface-active substances,and the composition of wastewater is very complicated.The wastewater has low acidity,big chromaticity,biochemical poor characteristics.The treatment process is very easy to produce foam and it is more difficult to handle.It is particularly important to explore an economical and practical treatment of the diosgenin pretreatment for biological treatment of diosgenin wastewater.In this paper,based on a large number of experiments,a method for pretreatment of diosgenin wastewater by iron carbon micro-electrolysis-Fenton oxidation process is proposed.Taking the wastewater of a diosgenin manufacturer in Huaxian County of Shaanxi Province as the research object,the pretreatment of diosgenin wastewater was studied.It was found that the process could significantly reduce the COD value and chroma of diosgenin wastewater and provide a guarantee for the biodegradation of diosgenin wastewater.The results of this paper are as follows:(1)Through single factor and orthogonal experiments,the optimum reaction conditions in the iron carbon micro-electrolysis stage were obtained as follows: the p H value was 3,the dosage of iron carbon micro-electrolytic filler was 45g/100 mL,the reaction time was 120 min,Aeration is controlled at 10-15mL/min.After the reaction,the pH of the effluent was adjusted to 9.0,the removal rate of COD was 40.2% and the chroma removal rate was 47.6%.The COD value decreased from 97000mg/L to 58006mg/L,and the chroma decreased from 11833 degrees to 6248 degrees.and the biodegradability of the wastewater was improved.The B/C value increased from 0.27 to 0.49.The main factors influencing the removal rate of COD were as follows: reaction time>p H value>aeration>iron and carbon filler dosage;The main factors affecting the chroma removal rate were pH value>aeration>iron and carbon filler dosage>reaction time.Iron carbon micro-electrolysis technology has a better treatment effect on diosgenin wastewater.(2)According to the single factor and orthogonal experiments,the optimum reaction conditions of the diosgenin wastewater treated by micro-electrolysis in Fenton oxidation process were as follows: the p H value was 3,the Fe2+concentration was 2500mg/L,the hydrogen peroxide dosage was 100mL/L,reaction time was 90 min,hydrogen peroxide dosing method for multiple dosing.After the reaction,the p H of the effluent was adjusted to 9.0,the removal rate of COD was 89.7% and the chroma removal rate was 84.5%.The COD value decreased from 97000mg/L to 9765mg/L,and the chroma decreased from 11833 degrees to 1767 degrees.Significantly improve the biodegradability of wastewater,B/C value rose to 0.63.The main factors affecting the removal rate of COD were as follows: pH value>Fe2+ concentration>hydrogen peroxide dosage>reaction time;the main factors affecting the removal rate of chroma were: hydrogen peroxide dosage>Fe2+ concentratio>pH value>reaction time.The effect of iron carbon micro-electrolysis and Fenton oxidation on the treatment of diosgenin wastewater is good.(3)The changes law of organic matters in treated diosgenin wastewater were studied by analysis IR,UV,GPC,HPLC,TOC and GC-MS spectra and it was confirmed that pretreatment could significantly improve the quality of wastewater.The biodegradability of wastewater was improved greatly after pretreatments of diosgenin wastewater of micro-electrolysis-Fenton oxidation process,it can meet the requirements of biochemical treatment.